6.23.2009

Pardon the cliche, but it's one of the holiest of Holy Grails of technology: Wireless power. And while early lab experiments have been able to "beam" electricity a few feet to power a light bulb, the day when our laptops and cell phones can charge without having to plug them in to a wall socket still seems decades in the future.Nokia, however, has taken another baby step in that direction with the invention of a cell phone that recharges itself using a unique system: It harvests ambient radio waves from the air, and turns that energy into usable power. Enough, at least, to keep a cell phone from running out of juice.While "traditional" (if there is such a thing) wireless power systems are specifically designed with a transmitter and receiver in mind, Nokia's system isn't finicky about where it gets its wireless waves. TV, radio, other mobile phone systems -- all of this stuff just bounces around the air and most of it is wasted, absorbed into the environment or scattered into the ether. Nokia picks up all the bits and pieces of these waves and uses the collected electromagnetic energy to create electrical current, then uses that to recharge the phone's battery. A huge range of frequencies can be utilized by the system (there's no other way, really, as the energy in any given wave is infinitesimal). It's the same idea that Tesla was exploring 100 years ago, just on a tiny scale.